Automatic switch.



F. A. LUNDQUIST. AUTOMATIC SWITCH.

APPLICATION FILED DEC. 2. 1916.

1 ,238, 1 63 Patented Aug. 28, 1917.

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FRANK A. LUNDQUIST, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOM- IPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC SWITCH.

Specification of Letters Patent.

Patented Au 28, 1917.

Application filed December 2, 1916. Serial No. 134,574.

To all whom it may concern:

Be it known that I. FRANK A. LUND- UIST, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Automatic Switches,of which the following is av full, clear, concise, and exactdescription.

This invention relates to automatic switches of the gravity operatedtype for use in telephone exchanges.

The object of the invention is to pro vide a. switch ofcompact'construction for rapidly connecting a subscribers line to anidle trunk line leading to a selector'switch or to an operatorsposition.

A feature of the invention is the positioning of cross bars to indicatethe idle or busy condition of trunk lines.

lVhile the principles of the invention are shown herein as applied to aline switch, they may be readily applied to a line finder by thoseskilled in the art.

In the drawings, Figure 1 shows a front elevation of the switch withoperating circuits; Fig. 2 is a perspective view of the brushes, showingtheir connection to the subscribers line; and Fig. "3 is aplan view of across bar.

The switch units are arranged to be mounted in a row on a frame 6 beforea contact panel 9. A brush carriage 7 and a rack 8 are slidably mountedon a ribbon 5 which is held at either end to the frame 6. The brushcarriage and the rack are normally held together by a spring 11, one endof which is secured to the upper end of the rack 8, the "other end beingsecured to the upper end of the carriage 7. A stepping magnet SM isprovided with an armature 12, pivoted at 46, which has pivoted at itsleft end a two-armed pawl 13. A spring 45 normally holds the pawl 13 inengagement with a pin 14 on the frame. A twoarmed pawl 15, pivoted "tothe frame, nor-- mally engages the teeth 16-of the rack '8, but when themagnet SM is energized, pawl 13 engages jaw 17 on pawl 15, retractingthe pawl and allowing the rack and brush carriage to fall. A bell-cranklever 20, pivoted at 4.7, is normally held by an arm 21 on the rack 8,and holds the contact springs 18 open and contacts 19 closed The lever20 will stay in normal position after the removal of arm 21 when theenergization of relay SM causes'the arm 23 of pawl 13 to engage a hook22 at the lower end of the lever. Upon the denergization of relay SM,however, spring 24: will pull the arm of lever 20 against a stop 48.When lever 20 is in this position, the energization of relay SMcauses'the pawl 13to engage the teeth 16 on the rack 8, and consequentlythe raising of the rack.

A stop member 25 is provided adjacent and associated with each pair ofmultiple contact strips 49 in the contact panel 9. The stop members 25are mounted in any convenient manner so as to permit rotation through asmall. arc and are movable longitudinally. Each stop member is providedwith projecting rods 26 as will be clearly seen in Fig. 3, one red beingprovided corresponding to each set of contacts 10. A pin 28 is mountednear the end of each stop member. A. spring 26 at the end of each stopmember tends to draw the stop member to the right, but is normallyprevented from doing so by the engagement of pin 28 with a plate 27which is mounted on the frame.

A gooseneck-shaped arm 29 is pivotedto the yoke 30 which is carried bythe brush carriage 7. At the lower end of the arm 29 a hook 31 isprovided, and is so placed that it will engage one of the projections 26on the first stop member 25 which is in normal position when the brushcarriage 7 is allowed to fall. A pair of brushes 32, 33 are insulatedlymounted at the upper end of the arm 29, and are so positioned that whensaid arm is rotated inrian anti-clockwise direction, after the hook 31has engaged a rod 26 and the stop member 25 has been moved to the right,the brush .32 will make contact with the upper one of a set 10 ofcontacts and the brush 33 with the lower one of said set. Two metalstrips 34 and 35 are insu-latedly mounted on a hinge 36 which is held ateither end in the frame 6. The brush 32 will make contact with the strip35 and the brush 33 with the strip '31 at the same time that contact ismade with contacts 10, as will be clearly seen in Fig. 2,. When thebrushes engage these strips, the strips turn on the hinge 36 so as toopen the off-normal contact ON, which is located near the upper end ofthe strip 34s Further details of construction will be understood fromthe following description of the operation of the switch.

When the subscriber at the substation indicated. at A removes thereceiver from its hook, he completes an energizing circuit for the relayLR from grounded battery, through the winding of the relay LR, wire 37,off-normal contact ON, wire 2, substa tion A, wire 1, wire 38, throughthe retardation coil BC to ground. The consequent energization of therelay LR completes a circuit from grounded battery, armature and frontcontact of relay LR, wire 39, back contact and armature 12 of relay SM,through the winding of the magnet SM to ground. The consequentenergization of the magnet SM breaks this circuit at the back contact ofthe armature of SM, but closes the wrings 50, thus establishing aholding circuit for said magnet from battery, armature and front contactof relay LR, wire 39, springs 50, contact spring 19, through the windingof the magnet SM to ground. The pulling up of armature 12 of magnet SMcauses the pawl 13 to engage the pawl 15, and release the rack 8 andbrush carriage 7 in the manner previously described. The fall of thecarriage and rack is arrested by the engagement of the hook 31 with arod 26 on the stop member associated with the first idle trunk lineencountered. This engagement turns the stop member 25 so as to allow thepin 28 to ride over the edge of the plate 27, and to close contactsprings 40 and 41. The spring 26 now pulls the stop member 25 to theright until its motion is limited by the engagement of a lug 42 on thestop member with a pawl 43 carried on the armature of the release magnetRel. This engagement completes a circuit for the slow acting relay 44from battery, through the winding of the relay 44, contact springs 40,wire 3, upper contact 10, brush 33, strip 34, wire 2, substation A, wire1, wire 38, through the coil BC to ground. The subscriber at the stationA is now connected through wire 1, strip 35, brush 32, contact 10, wire4, and through wire 2, strip 34, brush 33, contact 10 and wire 3 eitherto a first selector or to an operator, according as the exchange isautomatic or semi-automatic.

When the stop member 25 was drawn to the right, the engagement of thebrushes with the metal strips 32 and 33 opened the contact ON, therebybreaking the circuit for the relay LR which retracted its armature. Infalling back the armature of the relay LR broke the circuit holding upthe magnet SM which thereupon retracted its armature. The removal of thearm 23 of pawl 13 from engagement with hook 222 allowed lever 20 to turnin an anti-clockwise direction so that contact springs 18 close andsprings 19 open. A circuit is thereupon completed from grounded battery,armature and back contact of relay LR, spring 18, wire 39, back contactand armature of magnet SM, through the winding of the magnet SM toground. The consequent energization of the magnet SM causes theengagement of a tooth in the racks 8 by the pawl 13, and lifts the rackone step.

Since the circuit for the magnet SM is broken at the back contact of itsarmature, when it is energized it will intermittently fall back and pullup again until the rack S has been stepped back to normal position, atwhich time the arm 21, by raising lever 20, opens contact springs 18 andpermanently breaks the circuit for SM. The brush carriage 7 is notreturned to normal, however, since the rod 26 holds hook 31 as long asstop member 25 is in off-normal position.

At the close of the conversation the subscriber at A breaks at hisswitchhook the previously traced circuit for the relay 44, whichthereupon retracts its armature and closes a circuit for the releasemagnet from grounded battery, armature and contact of relay 44, contactsprings 41, through the winding of the release magnet Rel. to ground.The consequent attraction of the armature of the magnet Rel. forces pawl43 and lug 42 to the left until the pin 28 has moved beyond the verticaledge of the plate 27, at which time stop member 25 is rotated by aspring (not shown) until the pin 28 engages said edge. When the stopmember 25 moves to the left, the rod 26, pressing against the left jawof hook 31, frees arm 29 so that the spring 11 elevates brush carriage 7to normal. The yoke 30 is arranged to allow the lower end of the arm 21to ride over such rods 26 as may lie in its path during restoration. Theremoval of the brushes from engagement with the strips 34 and 35 allowsthem to be returned to normal by a spring (not shown), and the switch isnow ready for the next call.

What is claimed is:

1. In an automatic switch, a plurality of terminal strips, a gravityoperated brush to cooperate therewith, means for releasing said brush,and a plurality of longitudinally movable stop members extending acrossthe faces of said terminal strips arranged to arrest the movement of afalling brush.

2. In an automatic switch, a plurality of terminal strips, a gravityoperated brush to coiiperate therewith, means for releasing said brush,a plurality of longitudinally movable stop members extending across thefaces of said terminal strips arranged to arrest the movement of afalling brush, and means responsive to the engagement of a falling brushwith a stop member for moving said stop member longitudinally from thepath of subsequently falling brushes.

in an automatic switch, sets of multiple line terminals, alongitudinally movable stop member associated with each set of said lineterminals, means for maintaining said stop members in a definiteposition when the associated line terminals are in a certain electricalcondition, brushes arranged to travel over and make contact with saidline terminals, and mechanical means responsive to the position of saidstop members for controlling said brushes.

i. In an automatic switch, sets of multiple line terminals, alongitudinally movable stop member associated with each set of said lineterminals, means for maintaining said stop members in a definiteposition when associated line terminals are in a certain electricalcondition, brushes arranged to travel over and make contact with saidline terminals, members arranged to engage any one of said stop memberswhich is in normal position, and means responsive to such engagement forlongitudinally displacing said engaged member.

5. In an automatic switch, sets of multiple line terminals, alongitudinally movable stop member associated with each set of said lineterminals, means to maintain said stop members in a normal or anactuated position corresponding to the idle or busy condition of saidassociated line terminals a brush carriage, brushes on said carriagearranged to travel over and make contact with said line terminals, anengaging member carried by said brush carriage arranged to engage thefirst one of said stop members which is encountered in normal positionduring the travel of said carriage, means for initiating the travel ofsaid carriage. and a spring associated with each stop member for movingsaid stop member when engaged out of the path of movement ofsubsequently falling engaging members.

6. In an automatic switch, sets of multiple line terminals, alongitudinally movable stop member associated with each set of said lineterminals to denote by its position the idle or busy condition of saidassociated line terminals, a gravity operated brush carriage, brushes onsaid carriage arranged to travel over and make contact with said lineterminals, an engaging member carried by said brush carriage arranged toengage the first one of said stop members which is encountered in normalposition during the travel of said carriage, means for initiating thetravel of said carriage, and a spring associated With each stop memberfor moving said stop member when engaged out of the path of movement ofsubsequently falling engaging members and for causing said associatedbrushes to make contact with the selected terminals.

In witness whereof, I hereunto subscribe my name this 29th day ofNovember A. 1)., 1916.

FRANK A. LUNDQUIST.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Yatents. Washington, I). C.

